Photographic printing frame



(No Model.) 2 Sheets-Shet 1.

H. SACK.

PHOTOGRAPHIU PRINTING FRAME.

No. 563,888. Patented July 14, 1896.

(No Model.)

- 2 Sheets-Sheet 2. E SAGK. v PHOTOGRAPHIG PRINTING FRAME.

Patented July 14, 1896.

8 illlliillnlli1% UNITED STATES PATENT ()EEIcE.

IIUGOVSAOK, OF DUSSELDORF, GERMANY.

PHOTOGRAPHlC-PRINTING FRAM E.

SPECIFICATION forming part of Letters Patent No. 563,888, dated-July 14,1896.

Application filed May 1, 1896. Serial No. 589,877. (No model.) Patentedin Germany July 8, 1894, No. 83,219; in France April 1, 1895, No.246,275 ,"in Belgium April 1, 1895,No. 114,863; in England May 13, 1895,No. 9,437 in Austria June 27, 1895, No. 2,327, and in Hungary November5,1895,N0.4,301.

To all whom it may concern:

Be it known that I, HUGO SACK, a citizen of the German Empire, residingat Dusseldorf, in Rhenish Prussia, Empire of Germany, havemade certainnew and useful ImprovementsinPhotographic-PrintingFrames, (for which Ihave obtained patents in Germany, No. 83,219, dated July 8, 1894; inGreat Britain, No. 9,437, dated May 13, 1895; in France, No. 246,275,dated April 1, 1895; in Belgium, No. 114,863, dated April 1, 1895; inHungary, No. 4,301, dated November 5, 1895, and in Austria, No. 2,327,dated June 27, 1895,) of which the following is a specification.

My invention relates to improvements in pneumatic photo-printin gapparatus for copy in g drawings, &c., by the heliographic process.

In the earlier form of pneumatic bln e-printing frame invented by myselfand disclosed in my English patent, No. 15,757, of November 29, 1884, Ihave described an apparatus whereby very close and uniform adhesionbetween the sensitive paper and the original to be multiplied wasobtained by forcing both the sensitive paper and the original againstthe glass plate by means of atmospheric pressure. For this purpose therewas provided a rectangular frame into the recess of which was set aglass plate, and upon which was hinged an inner frame carrying a rubbercover. There was also provided means for exhausting the air between thecover and the glass, whereby said cover and glass were pressed togetherwith extremely great force by the atmospheric pressure on the externalsurfaces of the cover and glass. Experience has shown that there areseveral difficulties and defects attendant on this form of apparatus.These I have obviated in my improved apparatus, in the description ofwhich the drawbacks attendant on my former construction and the mannerin which they have been removed in my present apparatus will bespecified in detail.

In the accompanying drawings, Figure 1 is a perspective view of theapparatus ready for use. Fig. 2 is a similar view showing the apparatusclosed. Fig. 3 is a similar view to show the arrangement-for inspectinga single corner of the sensitized paper. Fig. 4 is a section of one sideof the device on an enlarged scale. Fig. 5 is a side view, also 011 anenlarged scale, of one of the pressure devices. Figs. 6 and 7 are viewssimilar to Figs. 4 and 5 of a modification.

1 represents the main frame of the apparatus, rectangular in form, onthe top of which is laid the glass plate 2, secured to the frame bystrips 3, as clearly shown in Fig. 6. Upon each side of the frame arepivoted arms 5, two or more in number, which terminate in portions 6,overhanging the plate when the arms are turned up, and on said arms aremounted slides 7, which carry rails 8. To the under side of one of saidrails is secured a rubber sheet 9, beneath which is preferably cementeda sheet 10, of canvas or other like material, for

the purpose of providing a vacuumchamber between the rubber sheet 9 andthe glass plate. Said sheet 9 has also a lower rubber facing 11 alongits edges to insure perfect tightness against the glass.

In order to firmly press the rails down upon the rubber sheet and securean air tight contact at the edges, I provide pressure devices such asare shown in Figs. 4, 5, 6, and 7, that shown in Figs. 4 and 5comprising a screw 12, working in a screw-threaded aperture in theportion 6 of the arm 5, and se-' cured to the rail 8 so as to raise orlower the same as the screw is screwed up or. down. The device disclosedin Figs. 6 and 7 comprises a lever 13, pivoted on the overhangingportion 6, and terminating in a cylindrical eccentric bearing 14,working in a socket 15, secured to the rail 8. It is clear that a turnof the lever from the position shown in dotted lines to that shown infull lines will depress the rail. 90

In order to hold together the rails after the pressure devices have beenoperated, I may make use of hooks on one rail engaging eyes on theadjacent rails at the corners, as shown in Fig. 2, but I prefer toemploy the device shown in Figs. 4 and 6, in which a lug 16, dependingfrom the rail 8, passes within a lug 17, rising from the frame 1, whenthe rail and slide are depressed.

For exhausting the air between the rubber sheet and the glass plate Iprovide a rubber tube 10, which is secured to the sheet, as shown inFig. 4. Through this tube the air may be exhausted and a vacuum createdby any suitable air-pump.

There are many important advantages attained in the apparatus hereindescribed. In the first place, the structure whereby the glass plate isplaced on the top of the main frame instead of in a recess therein is ofgreat practical importance.

In my former apparatus the glass plate was let down into a recess in theframe. These frames are made of large size, from four to ten feet long,and are much exposed to the sun and weather. Hence they are liable towarp.

If pressure is applied to the glass plate when it is placed in a warpedframe, the glass will be broken. Ilence it is of great importance todiscover at once if there is any warping of the frame, and to correct itif found. lVith my old style of frame it was extremely difficult todetect this warping, and also difficult to bring the frame to a properlevel, for this could only be done by a chisel, not by a plane; alsowith the old construction it was not possible to see if there was anair-tight contact at all points between the rail and the rubber sheet.This had to be done by pourin g in water and seeing whether it wouldpass between the two. Again, dirt would accumulate in the corners of theframe and prevent the hermetic closure. It will readily be understoodhow all these defects are eliminated by placing the glass plate on theuppermost plane of the frame.

Other important advantages result from the structure, whereby the sidesof the rubber sheet are held to the plane by four independent rails.

In the old structure, wherein the rubber sheet was secured to afour-sided frame, one side of which was hinged to the plate-frame, therewas great liability of fracture of the glass or of the rubber by reasonof the heavy rubber frame slipping from the hands. As the outer edge ofthe rubber frame would in such a case fall through a distance of severalfeet it is readily seen that much damage could be done. Moreover, itfrequently happened that one of the pressure levers on the hinged sideof the frame would be inadvertently left locked when the frame wasopened, in which case said lever would be damaged. Again, thearrangement of a heavy frame swinging from its side on another heavyframe was clumsy and awkward to handle, and with the larger sizesrequired two men to handle it.

My present arrangement of a rubber sheet secured along one edge to oneof the rails I find to be a very advantageous one. The

rubber does not support any weight but its own, and thus the danger ofmaking a hole in it, which existed when the rubber was contained in awooden frame, whether hinged or The rubber sheet is light not, isminimized.

and requires no exertion to handle, and can be readily operated by aboy. Again, it is very advantageous in that in rolling out the sheet ofrubber the creases in the drawing or tracing are straightened out,whereas in the old construction they were liable to be inclosed by theframe and rubber cover, which gave an imperfect print.

Having thus fully described my invention, what I claim is- I 1. I11 apneumatic photographic-printing frame, the combination with the mainframe and the glass plate supported thereon, of a hermetically-closingcover for the glass, said cover being flexible and free to be rolled upwhen not in use, rails, detached from the cover, for pressing the freeedges of the cover on the glass plate, means for exerting pressure onthe rails to obtain an air-tight contact at said edges between the coverand glass plate, and an air-exhaust pipe leading from the space betweenthe cover and plate, substantially as described.

2. In a pneumatic photographic-printing frame, the combination with themain frame,

and the glass plate supported thereon, of a flexiblehermetically-closing cover, as of rubber, for the glass plate, saidcover being secured at one of its edges to the corresponding edge of theframe and being free at its other edges, a rail for each side of theframe, independently pivoted at its own side of the frame and adapted torest 011 the corresponding edge of the cover, means for exertingpressure on the rails to obtain an air-tight contact between the coverand glass plate at the edges, and an air-exhaust pipe leading from thespace between the cover and plate, substantially as described.

3. In a pneumatic photographic-printing frame, the combination, with therectangular main frame, and the glass plate supported thereon, of ahermetically-closing cover for the glass plate, said cover beingflexible and free to be rolled up when not in use, means, independent ofeach other, for obtaining an air-tight contact between the cover andglass at each side of the cover, and an air-exhaust pipelcading from thespace between the cover and plate, substantially as described.

4. In a pneumatic photographic-printing frame, the combination with amain frame having a plane upper supporting-surface, of a glass platelaid thereon so as to be wholly above said frame, a flexiblehermeticallyclosing cover adapted to rest upon said plate, means forsecuring an air-tight contact between the covcr and glass at the edges,and an air-exhaust pipe leading from the space between the cover andplate, substantially as described.

In witness whereof I have hereunto set my hand this 30th day of April,1896.

HUGO SACK. Witnesses:

T. M. WRIGHT, W. F. BENNETT.

IOC

